Vacuum drying apparatus.



PATUNTUU MAY 14, 1907.

U. PAssBURG. VACUUM URYING APPARATUS.

APPLIO-ATION FILED JULY'27, 1905.

2 SHEETS-SHEET 1.

PATEN'A'UD MAY 14, 1907. E. PAssBURG. VACUUM DRYING APPARATUS.l

APPLICATION FILED JULYZ?, 1905. l

2 SHEETS-.SHEET 2.

u UNITED sTATEs/ PATENT oEEicE.

EME. PAssBURG, or BERLIN, GERMANY.`

vAcuuwl DRYING APPARATUS..

To alt whom-it 'may concern:l

Beit known that I, EMrL PAssBURG, a' subject of the German Emperor, residing at Berlin, in Germany, have'invented certain new and useful Improvementsin Vacuum Drying Apparatus for the Production of Coarse- Grained Materials from Liquids, of which the oration due to the vacuum, bubbles. are, formed which dry in this-shape and drop by l gravity'at the point where the bandsY pass round their supporting and driving rollers, or

vare loosened by Scrapers in such a manner that the coarse structure of the material is'y preserved and the lformation of pulverized materials prevented. The heating bclies.

and the drying bands' can be arranged in a horizontal or vertical direction as required. In the accompanying drawing Figure l is a vertical section of a vacuum drying -apparatus with vertical drying bands, Fig. 2 is a horizontal crosssection-through the casing upon a plane indicated bythe line 2 2 `in Fig. 1, showing the interior of `the apparatus in plan withthe Scrapers mand the feed tubes h omitted. Figs. 3,4 and.5 are detail views on an enlarged scale representing various means' for bringing the liquid on to the drying bands, Fig. '6 is a vertical longitudinal section showing a vacuum drying apparatus with horizontal dryin bands, Fig. 7 is a vertical cross-section, of ig. 6, Fi s. 8 and 9 are detail sections lshowingrnodiiications of the rollers which carry the drying bands'.

Referring to Figs. 1 and 2 the upright cylindricalfdrumv or casing V forms the vacuum chamber, which surrounds the vertical plates a tubes b or otherl suitable heating .means in4 which steam or hot water or another suitable heating medium suchasfhot air or the like is caused to circulate.` The heated fiuidmay be introduced through such means as tubes g.

'and may bedischarged through tubes r.

Endless bands c are mounted on pairs of ro- Speeicaton of Letters Patent.

Application, filed July 27,1905. Serial No. 271.418.

Patented May 14, 1907.

travel on said rollers as close as possible past the heating devices a or b. The axles of the rollers-maybe driven by. sprocket wheels s provided withchains t or by some other suitable means, from any suitable driving device (not shown). l L

For supplying lthe liquid to be dried to the bands, 'lower and upper` distributingv or feed Vtatable' rollers t' andyd and are caused to tubes e and h respectively-are used, which may receivel liquid from supply tubes 'u and are either provided with small closely arranged holes or tubular nozzles f (Fig. 3) or slots with-a filling of wick (Fig. 4) or without said filling (Fig. 5). The li uid flows from the openings on to thebands either inthe form of drops or. in a thin layer. The upwardly traveling surfaces of the bands are supplied witlrliquid by the lower distributing or feed tubes e and the downwardly traveling surfaces by the upper distributing or feed tubes h. i

at the particular rate of speed desired and the quantity of liquid supplied to the bands may lbe regulated by some such means as a valve ers i or d as the case may be, it will be dried to the extent desired. At the point where these bands pass round the rollers the dried material is completely or partly loosened and falls and by means of scrape'rs 'm and o any band is .completely removed therefrom. On

distributing tubes e and h;A r

Partitions W `may be arranged between the bands to prevent' the falling dried mat rial from coming in contactwith the b@ ds charged with theliquid and for the same purpose the upper rollers t may be given a (Fig. 8).' I l The dried falling material passes into the screw ,conveyer S and is removed therefrom either to undergo a supplementary drying 1n into a receptacle of known kind whenceit is removed by known means with or without the drylng bands are arranged 1n planes.

The drying bands may of course be driven dried material which may remainy on the a `drying cylinder with stirring apparatus ,or

p; so that when the liquid arrives at the rollp further movement of said bands they are Aat once again supplied with fresh liquid by thel larger diameter than the lower rollers d interruption of the vacuum in the drying apl horizontal i o The liquid flows from a receptacle. l through tubes u to the distributing yor feed tubes e and h, which-'distribute liquid in -the point where thebandc passes round the roller d the said'band passingthe distributing .tubes containing the liquid is again supplied with liquid from below throu h the tubes e, the distributionbeing' preferably eected in drops or in a thin layer. Instead of the dis` tributing tubes e and h'slot like openings can also be arranged from which the liquid iows in a thin layer and moistens the band-. The drops or thin layers of previously. concentrated and therefore thick or viscous liquid remain on the'lowei': surface vof the band c, owing toadhesion and form bubbles durilg the rapid evaporation by reason of the vacu'd um and when dried drop at .the point where the band passes round the rollers d and in lIn order that the bands c may pass the heatingV devices as closely as possible, the rollers" and i may be given a diameter slightljy7 smaller than the hei ht of said heatin del vices a. (Fig. 9) Te band c and the ing bodies cil may be arranged either vertically or horizontally in the casing. l

eat-

I claim as 'nyinventioli; l." In a vacuum drying apparatus the combination of heatingdevicesl located side by side, rollers at the ends of these heating devices, an endless transportingband passing over each pair of rollers, and two feed tubes for the liquid to be dried on the transporting band, the feed tubesbeing located at opposite ends of and on opposite sides of the corresponding heating device, substantially'as l endless `transporting band passingover each A pair of rollers, two'feed. tubes for theliquid to be dried on the transporting band, the feedtubes being located at opposite ends of and/ on opposite sides of the corresponding heating device, and a pair of Scrapers for the removal of the dried material from each band ,substantially as described.

Injtestimony whereof I affix my signature in lpresence of'two witnesses.

\ EMIL PASSBURG.

Witnesses:l

WOLDEMARHAUP'L-'` Louis LIEBENTHAL 

